Python: Amplitude Modulation with NumPy
In this video I show how generate amplitude modulation from a Python NumPy array.
The code for the tutorial is:
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| # Import libraries | |
| import numpy as np | |
| from scipy.io.wavfile import write | |
| # Properties of the wav | |
| sps = 44100 # DON'T change | |
| carrier_hz = 440.0 | |
| modulator_hz = 0.25 | |
| ac = 1.0 | |
| ka = 0.25 | |
| duration_s = 10.0 | |
| # Calculate the sine wave | |
| t_samples = np.arange(sps * duration_s) | |
| carrier = np.sin(2 * np.pi * carrier_hz * t_samples / sps) | |
| # Modulate the carrier | |
| modulator = np.sin(2 * np.pi * modulator_hz * t_samples / sps) | |
| envelope = ac * (1.0 + ka * modulator) | |
| modulated = envelope * carrier | |
| # Write the wav file | |
| modulated *= 0.3 | |
| modulated_ints = np.int16(modulated * 32767) | |
| write('amplitude-modulated.wav', sps, modulated_ints) |
